Telephone substation apparatus



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E w GENT TELEPHONE SUBSTATIONYAPPARATUS Filed Dc. 24., 1911.0

Fla@ v /45 Patented Oct. 6, 1942 TELEPHONE SUBSTATION APPARATUS Edgar W.- Gent, Morristown, N. J., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application December 24, 1940, serial No. 371,567

z claims. (ci. 179-103) 'I'his invention relates to telephone substation apparatus and more particularly to hand telephones included in such apparatus.

Telephone substation apparatus includes, generally, a signaling device, such as arlnger, for producing an audible signal when the station is being called. Such a ringer usually is positioned within amounting, such as a .telephone desk stand.

In some forms of such apparatusan appreciable loss may occur in the signal produced by the ringer due to the fact that the ringer is substantially enclosed by the mounting and also due toV the absorption of sound Waves by the fabric covering on the table, desk or other support on which the telephone stand is positioned. Consequently, the signal produced by the ringer may not be of suiiicient intensity to be heard by subscribers at some distance from the telephone.

Furthermore, the production of a signal clearly audible at fairly great distances from the telephone involves the use of ringers ofconsiderable size with attendant problems in the construction of mountings for hand telephones.

One object of this invention is to facilitate the attainment of an audible signal of relatively high intensity from signaling devices, such as fingers, at telephone substations.

Another object of this invention is to simplify the construction of telephone substation apparatus.

In accordance with one feature of this invention, a hand telephone is provided with a recess in the handle thereof and a complete ringer is mounted Within the recess, the recess being acoustically coupled to the atmosphere through apertures in the handle and preferably so designed that it constitutes a resonating chamber resonant to the characteristic frequency of the gong of the ringer.

The invention and the foregoing and other features thereof will be understood more clearly and fully from the following detailed description with reference to the accompanying drawing in which:

Fig. 1 is a side view of a hand telephone constructed in accordance with this invention, a portion of the handle being broken away to show details of construction more clearly;

Fig. 2 is a front view of the hand telephone shown in Fig. 1 with a portion of the handle broken away;

Fig. 3 is an enlarged detail perspective view of the actuating mechanism of the ringer included in the hand telephone illustrated in Figs. 1 and 2;

Fig. 4 is an enlarged perspective View of a 55 ringer suitable for use in a hand telephone constructed in accordance with the invention;

Fig. 5 is a fragmentary view partly in section of a hand telephone having in the handle thereof a ringer of the construction shown in Fig. 4; and

Figs. 6 and 7 are wiring diagrams showing illustrative substation circuits including hand telephones constructed in accordance with this invention.

Referring now to the drawing, the hand telephone illustrated inFigs. 1 and 2 comprises ahandle I Il, for example, of insulating material, having at opposite ends thereof recessed or cupshaped portions II and I2 in which a transmitter and a receiver, respectively, are mounted. The intermediate portion of the handle I0 is provided with a recess I3 which communicates with the atmosphere through a plurality of apertures I4 and which is closed, except for the apertures I4, by a plate member I5 secured to the handle by screws I 6.

Mounted within the recess I3 is a ringer, designated generally as I'I, which comprises a attened U-shaped permanent magnet I8 and an L-shaped pole-pieceI I9, as shown clearly in Fig. 3. An actuating coil 20 is secured upon an insulating sleeve or form 2| which is slidably mounted upon the arm 22 of the magnet I8 and which has affixed thereto a folded spring 23 carrying a metallic striker member 24. The actuating mechanism described may be secured to the plate member I5 as by screws 25 threaded into the pole-piece I9.

Also mounted within the recess I3 is a bell or gong 26, which is provided with a stud 21 force tted into a tap in the handle I0 and which is so positioned that its periphery is opposite the striker member 24.

When the coil 20 is energized by an alternating current, in a manner which will be described hereinafter, the coil and its supporting sleeve or form 2l execute a reciprocating movement along the arm 22 so that the striker member 24 impinges upon the gong 26 and an audible signal is produced. The gong 26, of course, will have a characteristic frequency. In order that a signal of high intensity may be realized, the chamber I3 and the apertures I4 communicating therewith are so designed in accordance with wellknown principles that the acoustic network defined thereby is resonant at the characteristic frequency of the gong 26A.

In a number of instances, for example in offices, two or more telephone sets may be mounted upon a common support or desk and d iiculty may be experienced in determining which of the sets is 4pole-pieces 3l. ported at its center by a yoke 34 andhas aflixed being called. This difllculty may b e overcome by providing each o!4 the handsets with a signal lamp 28 mounted in the recess I3 and connected in circuit with the ringer so that when the ringer is actuated, the lamp lights or flashes and provides a visual ringing signal. The handle I is provided with apertures in its sides opposite the lamp 28, in which suitable lenses 29 are mounted.

Another ringer construction suitable for use in hand telephones constructed in accordance with the invention is illustrated in Figs. 4 and 5 and comprises a pair of parallel bar magnets 30 having like poles opposite and connected by a pair of L-shaped pole-pieces 3I, a signal coil 32 on one of the pole-pieces 3I and a magnetic armature 33 having its ends opposite the tips oi the The armature is pivotally supthereto a pair of strikers 35 adapted to impinge upon a chime bar 36 secured to the yoke 34 by a bolt 31. l

The ringer shown in Fig. 4 is mounted in the recess I3 in the handle I0 as illustrated in Fig. 5, the recessl I3 and apertures I4 communicating therewith preferably being so designed that the acoustic network defined thereby is resonant to the characteristic frequency of chime bar 36. If desired, a signal lamp may be provided in the hand telephone shown in Fig. in the manner illustrated in Fig. 1.

Two illustrative substation circuits including hand telephones constructed in accordance with this invention are shown in Figs. 6 and '1 wherein L1 and L2 are the line conductors, 38 is the usual induction coil, 39 is a resistance, 40 and 4I are condensers and 42 is the usual plunger mechanism included in desk sets for actuating the line contacts. In both figures, the circuit illustrates the condition when the hand telephone is at rest on the mounting therefor and the plunger 42, accordingly, is depressed.

In the circuit illustrated in Fig. 6, the line contact assembly includes two contacts 43 and 44 which are open when the hand telephone is at rest on the mounting therefor. The ringer I1 and signal lamp 28 are connected in parallel and across the line L1 and Lz through conductors 45 and 46 and the condenser 4I. Normally, as is apparent, the transmitter and receiver circuits are open and when the ringing current is supplied to the line, the ringer I1 and signal lamp 28 areactuated. When the hand telephon is removed from the mounting the plunger 42 r ses and the contacts 43 and 44 close to complete the receiver and transmitter circuits, as will be apparent from the drawing.

In the circuit illustrated in Fig. '1, the line contact assembly includes three contacts 43, 44 and 41, the`contact 43 being connected to the transmitter, the contact 44 being connected to the receiver and the contact 41 being connected The contact 41 is closed so that the ringer I1 and signal lamp 28 are connected across the line Li and Lz, one connection being by way :i conductor 45, contact 41, a part of coil 38, and con denser 40 to L1 and the other connection being by way of conductor 46 and part of the induction coil 38 to Lz. When the hand telephone is removed from the mounting, the plunger 42 rises,4

whereby contacts 43 and 44 close to complete the transmitter and receiver circuits and contact 41 opens to break the ringing circuit.

It will be appreciated that in apparatus constructed in accordance with thisinvention, the ringer is located in such a position that the signal therefrom is not muilled or reduced in intensity by the telephone mounting or by the support on which the mounting rests and that, due in part tothe resonating system I3, I4, an audible signal of high intensity may be obtained. Furthermore, this invention obviates the use of a ringer in the desk stand and, hence, simplifies and facilitates the design andY construction of telephone substation apparatus, and, in addition, enables the attainment of an intense ringing signal with a to one terminal of the ringer I1 with which the signal lamp 28 is in parallel. When the hand telephone is at rest on the mounting therefor,

ringer of small size.

Although specific embodiments of the invention have been shown and described, it will be understood that they are but illustrative and that various modiiications may be made thereon without departing from the scope and spirit of this invention as defined in the appended claims.

What is claimed is:

1. A hand telephone comprising means denning a resonant chamber, an acoustic signaling member within said chamber and having a natural period at the resonant frequency of said chamber, and actuating means within said chamber for said signaling member including a coil reciprocably movable in the direction of its longitudinal axis, a magnet in cooperative relation with said coil, and a striker member actuable by said coil and positioned to strike said signaling member.

atmosphere, a wall portion of said intermediate portion adjacent said cavity being removed t0 form an opening into said cavity, a signal gong mounted in said cavity, a plate member removably secured to said intermediate portion and closing said opening, and electromagnetic actuating means for said gong within said cavity and I mounted upon said plate member, said cavity and apertures being constructed and arranged to define an acoustic network resonant at substantially the natural' period of said gong.

EDGAR W. GENT. 

